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MG Midget and Sprite Technical - Sump Gasket & Engine oil

Hello there,
Here is the probably the first of many posts now I have purchased a 72 midget and found this forum...
My midget is leaving its autograph of engine oil all over the drive/garage, so it is time to wipe the sump off and try a new gasket. I have a cork gasket and rear/front seals.
My question is, should I use blue hylomar as well? Has anyone out there got any tips for a perfect seal?
And what oil is everyone putting in, I have some good old 20/50 mineral oil, but does anyone recommend something more modern?

Thanks (there will be many more questions)

Ant
A Lomas

Ant - by all means give it a go; the sump is accessible from underneath..

I just use the gaskets and a little pva to hold them in place - others may use insta-gasket.

You will probably find that the leak is not from the front or rear seals on the sump but the back of the engine. There is a scroll seal and a half moon bracket which tries to keep the oil in..
http://www.flickr.com/photos/tobyanscombe/2987675640/ shows the bracket on the back of the crank and if you look at the right hand side of the crank (gearbox end) in this photo http://www.flickr.com/photos/tobyanscombe/2959006992/ you can see what looks like a couple of rings machined in - that is a screw which is supposed to throw the oil back into the engine and not let it out..


The slightest bit of wear in the crescent bracket means that it will leak - my money is on your engine leaking from there and there is bugger all you can do about it without pulling the engine. On the upside, think of it as a built in rust prevention mechanism ;-)
Toby Anscombe


It's not leaking, it's marking it's territory!
a borris

Thanks you guys.

I must admit I'm not that bothered about it "marking its territory" and I do subscribe to the rust prevention technique, but I am worried what the scrutineers and clark of the course have to say when I sprint and hillclimb next season!

Any suggestions on the oil?

Ant
A Lomas

The cheapest 20/50 you can find
Geoff Mears (1970 Midget)

If the oil is coming from the scroll, you need to check your crankcase breather: the ASeries is designed to run in Midgets etc with a vacuum provided by the inlet manifold (or carb, depending on date of vehicle manuf).

No vacuum = leak at scroll

Tons in the archive on this.

A
Anthony Cutler

Mr. Cutler's got it. Without some sort of pressure relief, normal engine operation will create pressure in the crankcase that can force oil out through the path of least resistance, usually the scroll. Ideally, a well set up breather will actually draw a slight vacuum, and help prevent marking of territory, chassis rust prevention, whatever you choose to call oil leaks!

Cheers,

-:G:-
Gryf Ketcherside

I usually set 'get if fixed and bring it back when you've fixed it'.

How much does it leak?

Daniel Thirteen-Twelve

Ant

Welcome to the world of Midgets, the only way to cure the A series oil leaks is to fit a k series.


Alex Sturgeon

Alex, not true at all (I know you say it in jest) - I had a race engine which never leaked a drop in 3 season's use, it was a very good build, it IS possible with care and attention to detail..
David Smith

Not sure about the UK midgets, but my '72 US
model has that little breather on the front
timing case cover that pipes crankcase fumes
up to the intake manifold. When the steel
wool in the timing case cover gets full up,
I can lose some oil as well. Be sure that
whole breather system is working.

chuck
c c

David

Yes the A series is a great engine and can do lots of tuning to it but with the K, it is just such a good look when your engine bay is just full of engine :-))))
Alex Sturgeon

Thanks for all the tips you guys.
I've found the crank case breather pipe and it just goes into the oil catch tank (same as the rocker cover breather).
I'm running a 40 single weber and the vacuum on the inlet manifold is blanked off. i've opened this and it is a lot more than a slight vacuum.
Is there an adapter to us this as vacuum or will it be too much..

Pictures included

A Lomas

Hi, earlier 1275's used a valve attached to the inlet manifold (item 62 on linked page). I think for your year the take off was from the carb bodies themselves).

I would think it would be possible to convert to the manifold vent, but I have no experience with Webers.

HTH
Mark

http://tinyurl.com/5fyg6w
Mark Whitmore

Morrosso evacusump. Especailly if you fit a twin choke carb. Its in vizzards book.
Brad
Brad (Sprite IV 1380)

[IMG]http://i2.photobucket.com/albums/y43/samol/IMG_0146.jpg[/IMG]

Here is my set up.
From your comments and a bit of searching, it sounds like I need to connect the crankcase breather pipe to either the K&N filter housing or preferably the inlet manifold.
I guess I will also need a PCV valve and/or an oil separator.

A few more quick questions.
Am I right in saying that the PCV valve is fitted to the breather pipe off the rocker cover not the lower crankcase one?
And will fitting a breather with and oil separator to the inlet manifold upset the oil air flow already set up by the weber carb?
Where can I get the bits for this? The PCV valve a bango to fit a breather to my inlet manifold and an oil separator?
Cheers again Ant


A Lomas

http://i2.photobucket.com/albums/y43/samol/IMG_0146.jpg
photo again sorry

A Lomas

Hi, the standard set up would be from the PCV valve to the front timing chain cover vent.
Sorry I'm not sure about the set up with the oil separator and weber but it has been mentioned on this site about aftermarket valves that may be cheaper than the original fit.

HTH
Mark
Mark Whitmore

I don't seem to have a vent on the timing cover!
A Lomas

Here we go again. :o)

From what I've learnt investigating my lack of a breather system, is that 1275 engines have a pot on the front of the timing cover, and a hose connects to this. Have a look at the Moss or MGOC web catalogues to see it.

The pipe goes to one of two places, depending on the engine version. On a CC engine it goes to a PCV valve on top of the inlet manifold. On the later CE engine it goes into a Y piece and into the carb bodies. IMHO the latter is a far better system, and is what's I'm converting mine to do.

None 1275 engines don't have the timing cover breather outlet. Instead they have a pot on a tappet chest cover, or a pipe on the rocker cover. My car is a bitsa in this respect - the rocker cover and timing cover are not from a 1275. I wonder if yours is like mine?

Ant
Ant Allen

This thread was discussed between 14/11/2008 and 17/11/2008

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.